org.apache.druid.query.lookup

Interface LookupExtractorFactory

All Superinterfaces:

com.google.common.base.Supplier<LookupExtractor>

public interface LookupExtractorFactory
extends com.google.common.base.Supplier<LookupExtractor>

Users of Lookup Extraction need to implement a LookupExtractorFactory supplier of type LookupExtractor. Such factory will manage the state and life cycle of an given lookup. If a LookupExtractorFactory wishes to support idempotent updates, it needs to implement the `replaces` method

Method Summary

Modifier and Type	Method and Description
boolean	close() This method will be called to stop the LookupExtractor upon Druid process stop.
default boolean	destroy() This method will be called to drop the LookupExtractor upon explicit user request to coordinator to drop this lookup.
LookupIntrospectHandler	getIntrospectHandler()
boolean	replaces(LookupExtractorFactory other) Deprecated.
boolean	start() This method will be called to start the LookupExtractor upon registered Calling start multiple times should return true if successfully started.

Methods inherited from interface com.google.common.base.Supplier

get

Method Detail

start

boolean start()

This method will be called to start the LookupExtractor upon registered Calling start multiple times should return true if successfully started.

Returns:

Returns false if is not successfully started the LookupExtractor otherwise returns true.

close

boolean close()

This method will be called to stop the LookupExtractor upon Druid process stop. This would be used, for example, to stop any thread pools it might have. Calling this method multiple times should always return true if successfully closed.

Returns:

Returns false if not successfully closed the LookupExtractor otherwise returns true

destroy

default boolean destroy()

This method will be called to drop the LookupExtractor upon explicit user request to coordinator to drop this lookup. In this method user can do additional cleanup (e.g. deleting disk persisted cache) not done simply when Druid process was being stopped to be restarted. Calling this method multiple times should always return true if successfully destroyed.

Returns:

Returns false if not successfully destroyed the LookupExtractor otherwise returns true

replaces

@Deprecated
boolean replaces(@Nullable
                             LookupExtractorFactory other)

Deprecated.

This method is deprecated and is not removed only to allow 0.10.0 to 0.10.1 transition. It is not used on a cluster that is running 0.10.1. It will be removed in a later release.

getIntrospectHandler

@Nullable
LookupIntrospectHandler getIntrospectHandler()

Returns:

Returns the actual introspection request handler, can return null if it is not supported. This will be called once per HTTP request to introspect the actual lookup.